And whyyyyyy does it work?

(I have way to much time on my hands today. )

Amount of time you want chocolate... = x

Double it = 2x

Add 5 = 2x+5

Multiply by 50 = 100x+250

Add 175y [where y=3 or 4 to bring addendum to 2004] = 100x + 2004

Subtract birth year = 100x + (2004- birth year) = 100x + [age]

So this calculation will work next year if you dink with the 175y where y will be 4 or 5...

(for what it's worth...)

And the original formula will work whether you want chocolate never to a million times a day, but the numbers manipulation gets hairy!